ICS85301AKT IDT, Integrated Device Technology Inc, ICS85301AKT Datasheet - Page 13

• Manufacturer Part Number: ICS85301AKT
• Manufacturer: IDT, Integrated Device Technology Inc
• Type: Clock Multiplexerr

Specifications of ICS85301AKT

• Number Of Clock Inputs: 2
• Mode Of Operation: Differential
• Output Frequency: 3000MHz
• Output Logic Level: LVPECL
• Operating Supply Voltage (min): 2.375V
• Operating Supply Voltage (typ): 2.5/3.3V
• Operating Supply Voltage (max): 3.465V
• Package Type: VFQFN
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 16
• Lead Free Status / RoHS Status: Not Compliant

T
IDT
This section provides information on power dissipation and junction temperature for the ICS85301.
Equations and example calculations are also provided.
1. Power Dissipation.
The total power dissipation for the ICS85301 is the sum of the core power plus the power dissipated in the load(s).
The following is the power dissipation for V
NOTE: Please refer to Section 3 for details on calculating power dissipated in the load.
2. Junction Temperature.
Junction temperature, Tj, is the temperature at the junction of the bond wire and bond pad and directly affects the reliability of the
device. The maximum recommended junction temperature for HiPerClockS
In order to calculate junction temperature, the appropriate junction-to-ambient thermal resistance
moderate air flow of 0 linear feet per minute and a multi-layer board, the appropriate value is 51.5°C/W per Table 6A below.
Therefore, Tj for an ambient temperature of 85°C with all outputs switching is:
This calculation is only an example. Tj will obviously vary depending on the number of loaded outputs, supply voltage, air flow,
and the type of board (single layer or multi-layer).
T
ABLE
ABLE
ICS85301
2:1, DIFFERENTIAL-TO-LVPECL MULTIPLEXER
™
The equation for Tj is as follows: Tj =
Tj = Junction Temperature
Pd_total = Total Device Power Dissipation (example calculation is in section 1 above)
T
85°C + 0.122W * 51.5°C/W = 91.3°C. This is well below the limit of 125°C.
/ ICS
JA
A
Single-Layer PCB, JEDEC Standard Test Boards
Multi-Layer PCB, JEDEC Standard Test Boards
NOTE: Most modern PCB designs use multi-layered boards. The data in the second row pertains to most designs.
Multi-Layer PCB, JEDEC Standard Test Boards
6A. T
6B. T
= Ambient Temperature
= Junction-to-Ambient Thermal Resistance
Power (core)
Power (outputs)
Total Power
™
2:1, LVPECL MULTIPLEXER
HERMAL
HERMAL
R
MAX
_MAX
R
ESISTANCE
ESISTANCE
= V
MAX
(3.465, with all outputs switching) = 90.09mW + 32.2mW = 122.3mW
= 32.2mW/Loaded Output pair
CC_MAX
* I
JA
EE_MAX
JA
FOR FOR
FOR
= 3.465V * 26mA = 90.09mW
JA
JA
CC
16-P
vs. 0 Air Flow (Linear Feet per Minute)
JA
= 3.465V, which gives worst case results.
P
by Velocity (Linear Feet per Minute)
* Pd_total + T
16 L
OWER
IN
VFQFN, F
EAD
TSSOP
C
A
ONSIDERATIONS
ORCED
137.1°C/W
51.5°C/W
89.0°C/W
13
0
0
C
ONVECTION
TM
devices is 125°C.
118.2°C/W
81.8°C/W
200
ICS85301 REV. B DECEMBER 22, 2006
106.8°C/W
78.1°C/W
JA
must be used. Assuming a
500